New route toward high-energy-density nanocomposites based on chain-end functionalized ferroelectric polymers

The synthesis and characterization of novel ferroelectric polymer based nanocomposites with high energy density is described. The approach includes the preparation of the ferroelectric polymers with phosphonic acid end-groups and subsequent utilization of the reactive terminal groups of the polymer for direct coupling with oxide fillers. The prepared nanocomposites have been carefully characterized by solid-state NMR, DMA, DSC, XRD, and TEM. The formation of covalent coupling between the polymer matrix and ZrO₂ fillers renders the nanocomposites with great stability and uniform filler dispersion. As a result of the intimating coupling, the interfacial interaction regions between the nanoparticles and the polymer matrix, which is responsible for high polarization under the applied fields, have been clearly observed in the dielectric spectra of the nanocomposites. Excellent breakdown strength and substantial enhancement in the energy density have been demonstrated in the nanocomposites. The improvement in the energy storage capability of the nanocomposites has been rationalized on the basis of the changes in polymer microstructures and the rise of the electric displacement induced by the incorporated nanofillers.